"This research has put science behind what was already the perceived wisdom - that exercise does more than just help your health, " he said yesterday.

"Anecdotally, and from research we have done at Loughborough, people feel a lot more alive and alert after exercise. You are more aware of your surroundings."

He added: "There is an increase in the blood flow to your brain when you do regular exercise.

"This concept of improving cognitive functions when you take exercise is not new. But now the evidence seems to be stacking up."

The German researchers cannot say why jogging helped improve mental faculties. But Sanna Stroth, a psychologist who worked on the study, said the hippocampus region - which is responsible for a number of memory functions - was the key.